A sensible piece

recognizing unilateral action of US alone was not what brought Iran to the negotiating table here

See for example this sentence

As noted, countries like India and South Korea, who don’t feel threatened by an Iran nuclear weapon, will be only too happy to find a pretext to break out of the sanctions—perhaps tentatively at first but in a rush as others do. It will be hard to argue the rationale for sanctions, which, from the perspective of nearly every nation, will have achieved their purpose—bringing Iran to the table to negotiate serious limitations on its nuclear program.

I particularly agree with this conclusion

Enacting new, tough sanctions in an effort to force Iran toward a “better” deal would mystify and alarm the rest of the world, isolating and weakening us. Such sanctions would crumble under their own weight —amounting to, as Shakespeare said, “sound and fury, signifying nothing.”